6 files changed, 140 insertions, 29 deletions

diff --git a/arch/ppc64/mm/init.c b/arch/ppc64/mm/init.c
index c02dc9809ca5..b3b1e9c1770a 100644
--- a/arch/ppc64/mm/init.c
+++ b/arch/ppc64/mm/init.c
@@ -552,27 +552,18 @@ void __init do_init_bootmem(void)
         /* Add all physical memory to the bootmem map, mark each area
          * present.
          */
-        for (i=0; i < lmb.memory.cnt; i++) {
-                unsigned long base, size;
-                unsigned long start_pfn, end_pfn;
-
-                base = lmb.memory.region[i].base;
-                size = lmb.memory.region[i].size;
-
-                start_pfn = base >> PAGE_SHIFT;
-                end_pfn = start_pfn + (size >> PAGE_SHIFT);
-                memory_present(0, start_pfn, end_pfn);
-
-                free_bootmem(base, size);
-        }
+        for (i=0; i < lmb.memory.cnt; i++)
+                free_bootmem(lmb_start_pfn(&lmb.memory, i),
+                             lmb_size_bytes(&lmb.memory, i));
 
         /* reserve the sections we're already using */
-        for (i=0; i < lmb.reserved.cnt; i++) {
-                unsigned long base = lmb.reserved.region[i].base;
-                unsigned long size = lmb.reserved.region[i].size;
+        for (i=0; i < lmb.reserved.cnt; i++)
+                reserve_bootmem(lmb_start_pfn(&lmb.reserved, i),
+                                lmb_size_bytes(&lmb.reserved, i));
 
-                reserve_bootmem(base, size);
-        }
+        for (i=0; i < lmb.memory.cnt; i++)
+                memory_present(0, lmb_start_pfn(&lmb.memory, i),
+                               lmb_end_pfn(&lmb.memory, i));
 }
 
 /*
diff --git a/arch/ppc64/mm/numa.c b/arch/ppc64/mm/numa.c
index c3116f0d788c..cb864b8f2750 100644
--- a/arch/ppc64/mm/numa.c
+++ b/arch/ppc64/mm/numa.c
@@ -440,8 +440,6 @@ new_range:
                 for (i = start ; i < (start+size); i += MEMORY_INCREMENT)
                         numa_memory_lookup_table[i >> MEMORY_INCREMENT_SHIFT] =
                                 numa_domain;
-                memory_present(numa_domain, start >> PAGE_SHIFT,
-                                                (start + size) >> PAGE_SHIFT);
 
                 if (--ranges)
                         goto new_range;
@@ -483,7 +481,6 @@ static void __init setup_nonnuma(void)
 
         for (i = 0 ; i < top_of_ram; i += MEMORY_INCREMENT)
                 numa_memory_lookup_table[i >> MEMORY_INCREMENT_SHIFT] = 0;
-        memory_present(0, 0, init_node_data[0].node_end_pfn);
 }
 
 static void __init dump_numa_topology(void)
@@ -695,6 +692,46 @@ new_range:
                                                      size);
                         }
                 }
+                /*
+                 * This loop may look famaliar, but we have to do it again
+                 * after marking our reserved memory to mark memory present
+                 * for sparsemem.
+                 */
+                addr_cells = get_mem_addr_cells();
+                size_cells = get_mem_size_cells();
+                memory = NULL;
+                while ((memory = of_find_node_by_type(memory, "memory")) != NULL) {
+                        unsigned long mem_start, mem_size;
+                        int numa_domain, ranges;
+                        unsigned int *memcell_buf;
+                        unsigned int len;
+
+                        memcell_buf = (unsigned int *)get_property(memory, "reg", &len);
+                        if (!memcell_buf || len <= 0)
+                                continue;
+
+                        ranges = memory->n_addrs;       /* ranges in cell */
+new_range2:
+                        mem_start = read_n_cells(addr_cells, &memcell_buf);
+                        mem_size = read_n_cells(size_cells, &memcell_buf);
+                        if (numa_enabled) {
+                                numa_domain = of_node_numa_domain(memory);
+                                if (numa_domain  >= MAX_NUMNODES)
+                                        numa_domain = 0;
+                        } else
+                                numa_domain =  0;
+
+                        if (numa_domain != nid)
+                                continue;
+
+                        mem_size = numa_enforce_memory_limit(mem_start, mem_size);
+                        memory_present(numa_domain, mem_start >> PAGE_SHIFT,
+                                       (mem_start + mem_size) >> PAGE_SHIFT);
+
+                        if (--ranges)           /* process all ranges in cell */
+                                goto new_range2;
+                }
+
         }
 }
 
diff --git a/include/asm-ppc64/lmb.h b/include/asm-ppc64/lmb.h
index cb368bf0f264..de91e034bd98 100644
--- a/include/asm-ppc64/lmb.h
+++ b/include/asm-ppc64/lmb.h
@@ -56,4 +56,26 @@ extern void lmb_dump_all(void);
 
 extern unsigned long io_hole_start;
 
+static inline unsigned long
+lmb_size_bytes(struct lmb_region *type, unsigned long region_nr)
+{
+        return type->region[region_nr].size;
+}
+static inline unsigned long
+lmb_size_pages(struct lmb_region *type, unsigned long region_nr)
+{
+        return lmb_size_bytes(type, region_nr) >> PAGE_SHIFT;
+}
+static inline unsigned long
+lmb_start_pfn(struct lmb_region *type, unsigned long region_nr)
+{
+        return type->region[region_nr].base >> PAGE_SHIFT;
+}
+static inline unsigned long
+lmb_end_pfn(struct lmb_region *type, unsigned long region_nr)
+{
+        return lmb_start_pfn(type, region_nr) +
+               lmb_size_pages(type, region_nr);
+}
+
 #endif /* _PPC64_LMB_H */
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 6c90461ed99f..b97054bbc394 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -487,6 +487,28 @@ struct mem_section {
         unsigned long section_mem_map;
 };
 
+#ifdef CONFIG_ARCH_SPARSEMEM_EXTREME
+/*
+ * Should we ever require GCC 4 or later then the flat array scheme
+ * can be eliminated and a uniform solution for EXTREME and !EXTREME can
+ * be arrived at.
+ */
+#define SECTION_ROOT_SHIFT      (PAGE_SHIFT-3)
+#define SECTION_ROOT_MASK       ((1UL<<SECTION_ROOT_SHIFT) - 1)
+#define SECTION_TO_ROOT(_sec)   ((_sec) >> SECTION_ROOT_SHIFT)
+#define NR_SECTION_ROOTS        (NR_MEM_SECTIONS >>  SECTION_ROOT_SHIFT)
+
+extern struct mem_section *mem_section[NR_SECTION_ROOTS];
+
+static inline struct mem_section *__nr_to_section(unsigned long nr)
+{
+        if (!mem_section[SECTION_TO_ROOT(nr)])
+                return NULL;
+        return &mem_section[SECTION_TO_ROOT(nr)][nr & SECTION_ROOT_MASK];
+}
+
+#else
+
 extern struct mem_section mem_section[NR_MEM_SECTIONS];
 
 static inline struct mem_section *__nr_to_section(unsigned long nr)
@@ -494,6 +516,10 @@ static inline struct mem_section *__nr_to_section(unsigned long nr)
         return &mem_section[nr];
 }
 
+#define sparse_index_init(_sec, _nid)  do {} while (0)
+
+#endif
+
 /*
  * We use the lower bits of the mem_map pointer to store
  * a little bit of information.  There should be at least
@@ -513,12 +539,12 @@ static inline struct page *__section_mem_map_addr(struct mem_section *section)
 
 static inline int valid_section(struct mem_section *section)
 {
-        return (section->section_mem_map & SECTION_MARKED_PRESENT);
+        return (section && (section->section_mem_map & SECTION_MARKED_PRESENT));
 }
 
 static inline int section_has_mem_map(struct mem_section *section)
 {
-        return (section->section_mem_map & SECTION_HAS_MEM_MAP);
+        return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP));
 }
 
 static inline int valid_section_nr(unsigned long nr)
diff --git a/mm/Kconfig b/mm/Kconfig
index cd379936cac6..fc644c5c065d 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -89,3 +89,12 @@ config NEED_MULTIPLE_NODES
 config HAVE_MEMORY_PRESENT
         def_bool y
         depends on ARCH_HAVE_MEMORY_PRESENT || SPARSEMEM
+
+#
+# Architectecture platforms which require a two level mem_section in SPARSEMEM
+# must select this option. This is usually for architecture platforms with
+# an extremely sparse physical address space.
+#
+config ARCH_SPARSEMEM_EXTREME
+        def_bool n
+        depends on SPARSEMEM && 64BIT
diff --git a/mm/sparse.c b/mm/sparse.c
index b54e304df4a7..b2b456bf0a5d 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -13,7 +13,26 @@
  *
  * 1) mem_section       - memory sections, mem_map's for valid memory
  */
-struct mem_section mem_section[NR_MEM_SECTIONS];
+#ifdef CONFIG_ARCH_SPARSEMEM_EXTREME
+struct mem_section *mem_section[NR_SECTION_ROOTS]
+        ____cacheline_maxaligned_in_smp;
+
+static void sparse_index_init(unsigned long section, int nid)
+{
+        unsigned long root = SECTION_TO_ROOT(section);
+
+        if (mem_section[root])
+                return;
+        mem_section[root] = alloc_bootmem_node(NODE_DATA(nid), PAGE_SIZE);
+        if (mem_section[root])
+                memset(mem_section[root], 0, PAGE_SIZE);
+        else
+                panic("memory_present: NO MEMORY\n");
+}
+#else
+struct mem_section mem_section[NR_MEM_SECTIONS]
+        ____cacheline_maxaligned_in_smp;
+#endif
 EXPORT_SYMBOL(mem_section);
 
 /* Record a memory area against a node. */
@@ -24,8 +43,13 @@ void memory_present(int nid, unsigned long start, unsigned long end)
         start &= PAGE_SECTION_MASK;
         for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) {
                 unsigned long section = pfn_to_section_nr(pfn);
-                if (!mem_section[section].section_mem_map)
-                        mem_section[section].section_mem_map = SECTION_MARKED_PRESENT;
+                struct mem_section *ms;
+
+                sparse_index_init(section, nid);
+
+                ms = __nr_to_section(section);
+                if (!ms->section_mem_map)
+                        ms->section_mem_map = SECTION_MARKED_PRESENT;
         }
 }
 
@@ -85,6 +109,7 @@ static struct page *sparse_early_mem_map_alloc(unsigned long pnum)
 {
         struct page *map;
         int nid = early_pfn_to_nid(section_nr_to_pfn(pnum));
+        struct mem_section *ms = __nr_to_section(pnum);
 
         map = alloc_remap(nid, sizeof(struct page) * PAGES_PER_SECTION);
         if (map)
@@ -96,7 +121,7 @@ static struct page *sparse_early_mem_map_alloc(unsigned long pnum)
                 return map;
 
         printk(KERN_WARNING "%s: allocation failed\n", __FUNCTION__);
-        mem_section[pnum].section_mem_map = 0;
+        ms->section_mem_map = 0;
         return NULL;
 }
 
@@ -114,8 +139,9 @@ void sparse_init(void)
                         continue;
 
                 map = sparse_early_mem_map_alloc(pnum);
-                if (map)
-                        sparse_init_one_section(&mem_section[pnum], pnum, map);
+                if (!map)
+                        continue;
+                sparse_init_one_section(__nr_to_section(pnum), pnum, map);
         }
 }